178 citations · 971 across the 39 of their papers we have counts for
39 papers
Finite-temperature spin diffusion in the two-dimensional XY model
Erik Fitzner, Byungjin Lee, Junhyeok Hur +4
We present a combined theory-experiment study to quantify spin diffusion in the square lattice quantum spin-1/2 XY model at finite temperature. On the theory side, we leverage a re…
Thermometry for a Kagome Lattice Dipolar Rydberg Simulator
Erik Fitzner, Igor Lesanovsky, Björn Sbierski
We propose an accurate thermometry approach for Rydberg atom tweezer arrays combining data from correlation and local susceptibility measurements with a theoretical high-temperatur…
Collective cluster nucleation dynamics in quantum magnets
Philip Osterholz, Fabio Bensch, Shuanghong Tang +4
Strongly interacting many-body systems exhibit collective properties that emerge from complex correlations among microscopic degrees of freedom. These cooperative phenomena govern…
High-temperature series expansion of the dynamic Matsubara spin correlator
Ruben Burkard, Benedikt Schneider, Björn Sbierski
The high-temperature series expansion for quantum spin models is a well-established tool to compute thermodynamic quantities and equal-time spin correlations, in particular for fru…
Dynamic correlations of frustrated quantum spins from high-temperature expansion
Ruben Burkard, Benedikt Schneider, Björn Sbierski
For quantum spin systems in equilibrium, the dynamic structure factor (DSF) is among the most feature-packed experimental observables. However, from a theory perspective it is ofte…
Pseudo-Majorana functional renormalization for frustrated XXZ spin-1/2 models with field or magnetization along the spin-Z direction at finite temperature
Frederic Bippus, Benedikt Schneider, Björn Sbierski
The numerical study of high-dimensional frustrated quantum magnets remains a challenging problem. Here we present an extension of the pseudo-Majorana functional renormalization gro…
Dipolar ordering transitions in many-body quantum optics: Analytical diagrammatic approach to equilibrium quantum spins
Benedikt Schneider, Ruben Burkard, Beatriz Olmos +2
Quantum spin models with a large number of interaction partners per spin are frequently used to describe modern many-body quantum optical systems like arrays of Rydberg atoms, atom…
Taming spin susceptibilities in frustrated quantum magnets: Mean-field form and approximate nature of the quantum-to-classical correspondence
Benedikt Schneider, Björn Sbierski
In frustrated magnetism, the empirically found quantum-to-classical correspondence (QCC) matches the real-space static susceptibility pattern of a quantum spin- model with its…
Temperature flow in pseudo-Majorana functional renormalization for quantum spins
Benedikt Schneider, Johannes Reuther, Matías G. Gonzalez +2
We implement the temperature flow scheme first proposed by Honerkamp and Salmhofer in Phys.~Rev.~B 64, 184516 (2001) into the pseudo-Majorana functional renormalization group metho…
Pseudo-fermion functional renormalization group for spin models
Tobias Müller, Dominik Kiese, Nils Niggemann +5
For decades, frustrated quantum magnets have been a seed for scientific progress and innovation in condensed matter. As much as the numerical tools for low-dimensional quantum magn…
Magnetism in the two-dimensional dipolar XY model
Björn Sbierski, Marcus Bintz, Shubhayu Chatterjee +3
Motivated by a recent experiment on a square-lattice Rydberg atom array realizing a long-range dipolar XY model [Chen et al., Nature (2023)], we numerically study the model's equil…
Spectral representation of Matsubara n-point functions: Exact kernel functions and applications
Johannes Halbinger, Benedikt Schneider, Björn Sbierski
In the field of quantum many-body physics, the spectral (or Lehmann) representation simplifies the calculation of Matsubara n-point correlation functions if the eigensystem of a Ha…
Taming pseudo-fermion functional renormalization for quantum spins: Finite-temperatures and the Popov-Fedotov trick
Benedikt Schneider, Dominik Kiese, Björn Sbierski
The pseudo-fermion representation for quantum spins introduces unphysical states in the Hilbert space which can be projected out using the Popov-Fedotov trick. However, sta…
Scaling collapse of longitudinal conductance near the integer quantum Hall transition
E. J. Dresselhaus, B. Sbierski, I. A. Gruzberg
Within the mature field of Anderson transitions, the critical properties of the integer quantum Hall transition still pose a significant challenge. Numerical studies of the transit…
Quantitative functional renormalization for three-dimensional quantum Heisenberg models
Nils Niggemann, Johannes Reuther, Björn Sbierski
We employ a recently developed variant of the functional renormalization group method for spin systems, the so-called pseudo Majorana functional renormalization group, to investiga…
Identifying Majorana vortex modes via non-local transport
Björn Sbierski, Max Geier, An-Ping Li +3
The combination of two-dimensional Dirac surface states with s-wave superconductivity is expected to generate localized topological Majorana zero modes in vortex cores. Putative ex…
Numerical evidence for marginal scaling at the integer quantum Hall transition
E. J. Dresselhaus, B. Sbierski, I. A. Gruzberg
The integer quantum Hall transition (IQHT) is one of the most mysterious members of the family of Anderson transitions. Since the 1980s, the scaling behavior near the IQHT has been…
Frustrated Quantum Spins at finite Temperature: Pseudo-Majorana functional RG approach
Nils Niggemann, Björn Sbierski, Johannes Reuther
The pseudofermion functional renormalization group (PFFRG) method has proven to be a powerful numerical approach to treat frustrated quantum spin systems. In its usual implementati…
Criticality of two-dimensional disordered Dirac fermions in the unitary class and universality of the integer quantum Hall transition
Björn Sbierski, Elizabeth J. Dresselhaus, Joel E. Moore +1
Two-dimensional (2D) Dirac fermions are a central paradigm of modern condensed matter physics, describing low-energy excitations in graphene, in certain classes of superconductors,…
Non-Anderson critical scaling of the Thouless conductance in 1D
Björn Sbierski, Sergey Syzranov
We propose and investigate numerically a one-dimensional model which exhibits a non-Anderson disorder-driven transition. Such transitions have recently been attracting a great deal…
Disorder correction to the minimal conductance of a nodal-point semimetal
Zheng Shi, Björn Sbierski, Piet W. Brouwer
We consider the disorder-induced correction to the minimal conductance of an anisotropic two-dimensional Dirac node or a three-dimensional Weyl node. An analytical expression is de…
Spectrum-wide quantum criticality at the surface of class AIII topological phases: An "energy stack" of integer quantum Hall plateau transitions
Björn Sbierski, Jonas Karcher, Matthew S. Foster
In the absence of spin-orbit coupling, the conventional dogma of Anderson localization asserts that all states localize in two dimensions, with a glaring exception: the quantum Hal…
Strong disorder in nodal semimetals: Schwinger-Dyson--Ward approach
Björn Sbierski, Christian Fräßdorf
The self-consistent Born approximation quantitatively fails to capture disorder effects in semimetals. We present an alternative, simple-to-use non-perturbative approach to calcula…
Topological invariants for the Haldane phase of interacting SSH chains -- a functional RG approach
Björn Sbierski, Christoph Karrasch
We present a functional renormalization group approach to interacting topological Green function invariants with a focus on the nature of transitions. The method is applied to chir…